tie not working; harmonica midi instrument wanted

[Carl J. Weber]

Hi,

A few baby questions. I just started a few days ago with LilyPond.

1. In the second measure, the second tie is good on the .midi playback, but in that measure, the first tie doesn't work, and the notes are played separately, though tied in the visual staff.

2. I'm writing a method for harmonica, and I would like to change the midi instrument to harmonica with the hope of getting a non-articulated slur.

Your help is greatly valued,

Carl


    \version "2.16.2"

melody = \relative c' {
  \clef treble
  \key g \major
  \time 4/4

d8. e16 \times 2/3 { g8 bes( b )}d8. b16~ b4 
\acciaccatura des8 d8. b16~  b4 \acciaccatura des8 d8. b16~  b4 
d,8. e16 \times 2/3 { g8 bes( b )}d8. b16~  b4
\acciaccatura bes8 b8. g16 e8. g16~ g4 r4


}

\score {
  \new Staff \melody
  \layout { }
  \midi {\tempo 4 = 120}
}